Background: Adjuvant ipilimumab improves survival in stage III melanoma. Adjuvant nivolumab improves progression-free survival as compared to ipilimumab with reduced toxicity. Checkpoint 067 showed that the combination of ipilimumab and nivolumab is more active in advanced melanoma than either agent alone. The Brown University Oncology Research Group sought to evaluate dual checkpoint inhibition in the adjuvant setting. This may be particularly beneficial to patients with melanoma with low PD-L1 expression. To balance safety and efficacy, the combination of low dose ipilimumab and standard dose nivolumab was investigated. Methods: Patients with stage IIc, III and resected stage IV disease are eligible. No prior treatment for melanoma other than surgery or radiation was allowed. All patients received nivolumab 3mg/kg (maximum 240 mg) every 2 weeks and ipilimumab 1mg/kg every 6 weeks for 6 months. The primary goal is to determine the toxicity of adjuvant ipilimumab and nivolumab in patients with melanoma. Unacceptable toxicity has been defined as the development of grade 4 hematologic toxicity (neutropenia or thrombocytopenia), any transient grade ≥3 or persistent grade 2 treatment-related non-hematologic toxicity that prevents completion of the planned 6 month course of treatment in more than 35% of the enrolled patients; thus, if such events occur in 10 or more patients out of 25 evaluable patients, the study will have exceeded the limit for unacceptable adverse events. Secondary objectives are to determine the recurrence-free and overall survival. Results: Between August 2016 and August 2017, 17 patients have been enrolled, 11 male and 6 female. Median age is 59 (range 25-84). Twelve patients were Stage III disease, 2 patients were stage IIC and 3 were stage IV. Conclusions: BrUOG 324 represents one of the first trials investigating adjuvant dual checkpoint inhibition in melanoma. Preliminary safety and efficacy are being assessed. Acknowledgements: This study was supported in part by the Washington Trust Company and LIFEcycle Clinical trial information: NCT02656